Research conducted on this grant has established periodontal disease as a significant risk factor (P=0.0033) for preterm delivery and low birth weight (PLBW) in humans. Data from a case-control study of 124 mothers demonstrate that pregnant women with generalized periodontitis (i.e. greater than or equal to 60% of sites with 3 or more mm of attachment loss) have an adjusted odds ratio of 7.5 for having a PLBW. the risk of having PLBW as a result of periodontal infection is of greater magnitude than the risk attributable to smoking or alcohol usage. This continuation proposal seeks to reveal new data regarding the attributable risk and molecular basis for this newly observed association. In t his continuation proposal we plan to conduct a perspective study of pregnant women to quantify the added burden of periodontal infection using odds ratios and attributable risk for PLBW, analyzing for possible confounders. We will incorporate periodontal disease variables such as measures of disease extent, severity, microbial specificity and local inflammatory mediator secretion, in addition to traditional risk variables to form new multifactorial risk assessment models for PLBW. We will determine whether periodontal crevicular fluid levels of PGE2 or IL-1beta area associated with preterm delivery, premature rupture of membranes (PROM) or impaired fetal growth. This five year prospective study on over 2500 pregnant women will enable us to confirm the association between periodontal disease and PLBW, controlling for potential obstetric confounders such as age, race, nutrition, bacterial vaginosis, prenatal care and behavioral variables.